The assignee manufactures and sells various embodiments of measuring devices equipped with rope probes. These measuring devices usually include a device housing, in which a measuring device electronics is accommodated and on which a probe in rope, cable, tubular or rod form is mounted. These ropes, cables, tubes or rods are referred to herein generically as elongated units. Other common generic references include rope, or rope probes. Such elongated units are used e.g. in the capacitive measuring technology as an electrode, which is introduced into a container holding a medium. As a function of the fill level of the medium, the capacitance of the capacitor, of which one electrode is the elongated unit, changes, and, consequently, the fill level can be determined and/or monitored therefrom. In another method of measurement, e.g. electromagnetic pulses are sent along the elongated unit immersed in the medium. In this case, the elongated unit serves as a waveguide. From the signal reflected from the upper surface of the medium, the fill level can likewise be derived. Another application is represented e.g. by a conductive probe, in which case the electrical resistance of the medium is measured. Here, fill level is detected by the arrangement of multiple elongated units at different heights.
These measuring devices with an elongated unit are usually mounted to, or on, a container containing the medium to be measured, with the device housing frequently being secured in or on a container wall such that the elongated unit extends into the interior of the container and into the medium. The elongated units are either themselves conducting or else they at least have an electrical conductor inside. The elongated units are also, if necessary, coated externally with an electrically insulating layer. This layer provides protection against short-circuiting or e.g. also protection against aggressive media. Usually, the elongated units are connected with a measuring device electronics, in which the measurement signals are produced, or processed, as the case may be. The electronics, in turn, is usually connected with a measuring, or control, room, or with another superordinated unit, in which the fill level measured values are evaluated and processed.
A problem associated with these procedures is that the elongated units must be adapted to different conditions, i.e. they must be longer, or shorter, depending on the dimensions of the container. They must also, if necessary, be capable of being exchanged, when e.g. the medium attacks, or deteriorates, the elongated units. In such case, it should be possible that the elongated units can be replaced simply.